a dumb script to toggle audio input/output mute

mute-control.sh

#!/bin/bash
# a dumb script to toggle audio input/output mute

class="$1"
state="$2"
target="$3"
device="$4"

default_device=""
default_state=""
kind=""

function error () { echo "$@" >&2; }

function errorexit () { error "$@"; exit 1; }

function get_default_device () {
    search=Sink
    [[ $class == input ]] && search=Source
    _device=$(pactl info | grep -oP "(?<=\Default $search: ).*")
    echo "$_device"
}

function get_default_state () {
    filter=sinks
    [[ $class == input ]] && filter=sources
    _state=$(pactl list $filter \
        | grep -oE '^\s+(Name|Mute):.*' \
        | sed 's/^\s*//' \
        | grep "Name: $default_device" -B0 -A1 \
        | tail -1 \
        | cut -d" " -f2
    )
    if [[ $_state == yes ]]; then
        _state=true
    else
        _state=false
    fi
    echo "$_state"
}

function show_help {
    NAME=${0/**\//}
    echo -ne "
    \e[1m$NAME\e[0m - a dumb script to control audio in/out mute state
    
    \e[4mUsage:\e[0m
        $NAME CLASS [STATE] [FILTER [NAME]]

    \e[4mOptions:\e[0m
        \e[1mCLASS\e[0m   device class to work on:
                    in, source, mic         audio input 
                    out, sink, speaker      audio output
        \e[1mSTATE\e[0m   desired mute state:
                    toggle, -1            * toggle device muting
                    mute, true, 1           mute device(s)
                    unmute, false, 0        unmute devices
        \e[1mFILTER\e[0m  choose which device(s) to work on:
                    -d, --default         * default device
                    -a, --all               all devices (all follow default device)
                    -s, --sink, --source    sink or source named \e[1mNAME\e[0m
        \e[1mNAME\e[0m    device name or index if \e[1mFILTER\e[0m is -s, --sink or --source

        default value is indicated by an asterisk.
    " \
    | sed 's/^ \{4\}//'
    exit 1;
}

if [[ $1 == "--help" ]] || [[ $1 == "-h" ]]; then show_help; fi

[[ -z $state ]] && state=toggle
[[ -z $target ]] && target=default

case $class in
    source*|in*|mic*)      class=input;  kind=source;;
    sink*|out*|spk|speak*) class=output; kind=sink;;
    -*) target="$1"; target_lookahead=class;;
    *) errorexit "unknown device class '$class'";;
esac

case $state in
    mute|yes|true|1)   state=true;;
    unmute|no|false|0) state=false;;
    toggle|2)          state=toggle;;
    -*)
        if [[ $target_lookahead == class ]]; then
            device="$2"
        else
            target_lookahead=state
            target="$2"
            device="$3"
        fi
        ;;
    *) errorexit "unknown state '$state'";;
esac

case $target in
    --default|-d|default)
        target=default
        default_device=$(get_default_device)
        devices="$default_device"
        ;;
    --sink|--source|-s)
        target=single
        [ -z "$device" ] && errorexit "unknown $class $kind: ''"
        devices="$device"
        ;;
    --all|-a)
        target=all
        if [[ $class == input ]]; then
            devices=$(pactl list sources short | grep -vP '\.monitor' | cut -f1)
        else
            devices=$(pactl list sinks short | cut -f1)
        fi
        ;;
    *) errorexit "unknown filter '$target'";;
esac

if [[ $state == toggle ]] && [[ ! $target == single ]]; then
    default_device=$(get_default_device)
    default_state=$(get_default_state)
    state=true
    [[ $default_state == true ]] && state=false
fi

[ -z "$devices" ] && errorexit "could not find $class $kind '$devices'"

for device in $devices; do
    echo "$kind, $device, $state"
    pactl set-$kind-mute "$device" "$state"
done